Android特效专辑（七）——飞机升空特效，一键清理缓存，灵活运用属性动画
最近的几篇博文反响还不错，也会继续的写下去的，关于这些特效的专辑，大多数也是借鉴大神的，最近由于工作的关系，会深入的了解一下Android BLE与硬件设备的串口通讯相关的内容，也会时不时的分享出来，当然，大家是一起学习，我毕竟也是初学者，今天讲的是小火箭的动画效果，用到了基础动画做了一些偷梁换柱的事情，明天还是后天，再更新一个心型起泡飞舞的特效，就不会这么持续的更新特效专辑这一系列了，毕竟《Only》这个软件也正在开发当中，最重要的还是交互，不是特效，特效多了反而会鸡肋，并且机型适配方面可能导致一些不确定的因素也是有的，所以，这几天可能会多分享一些蓝牙相关的东西了，当然，会持续的更新Android实用案例这个系列，很多的Android技术等你一起来玩。
我们先来看看今天的效果图吧：
截图
感觉是不是挺好玩的？其实，我其实就是用了三张图片，用黑色背景我们看看这三张图片
好的，知道了这三张图片，我们在res文件下新建一个anim文件夹，然后把他们三个的动画加上
cloud.xml
<?xml version="1.0" encoding="utf-8"?><set xmlns:android="http://schemas.android.com/apk/res/android" > <alpha android:duration="800" android:fromAlpha="0" android:startOffset="300" android:toAlpha="1.0" > </alpha> <translate android:duration="800" android:fromYDelta="100%" android:interpolator="@android:anim/accelerate_interpolator" android:startOffset="300" android:toYDelta="0%" /> <alpha android:duration="500" android:fromAlpha="1.0" android:startOffset="2050" android:toAlpha="0" > </alpha> <translate android:duration="650" android:fromYDelta="0%" android:startOffset="2050" android:toYDelta="100%" /></set>launcher.xml
<?xml version="1.0" encoding="utf-8"?><set xmlns:android="http://schemas.android.com/apk/res/android" > <translate android:duration="200" android:fromYDelta="100%" android:startOffset="2050" android:toYDelta="0%" /> <alpha android:duration="450" android:fromAlpha="1.0" android:startOffset="2250" android:toAlpha="0" > </alpha></set>rocket.xml
<?xml version="1.0" encoding="utf-8"?><set xmlns:android="http://schemas.android.com/apk/res/android" > <translate android:duration="500" android:fromYDelta="100%" android:toYDelta="-5%p" /> <translate android:duration="500" android:fromYDelta="0%p" android:startOffset="500" android:toYDelta="4%p" /> <translate android:duration="500" android:fromYDelta="0%p" android:startOffset="1000" android:toYDelta="-1.5%p" /> <translate android:duration="300" android:fromYDelta="0%p" android:startOffset="1750" android:toYDelta="8%p" /> <translate android:duration="400" android:fromYDelta="0%p" android:interpolator="@android:anim/accelerate_interpolator" android:startOffset="2050" android:toYDelta="-108%p" /></set>activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/root" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/black" > <ImageView android:id="@+id/cloud" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:background="@drawable/cloud" android:visibility="invisible" /> <ImageView android:id="@+id/launcher" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:src="@drawable/launcher" android:visibility="invisible" /> <ImageView android:id="@+id/rocket" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:paddingLeft="8dp" android:src="@drawable/rocket" android:visibility="invisible" /> <Button android:id="@+id/getup" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:text="启动火箭" android:textColor="#ffffff" android:textSize="20dp" /></RelativeLayout>三个动画，然后就是布局，一个按钮启动，然后三张图片显示出来并且出来一个动画，是不是思路越来越清晰了？MainActivity
package com.lgl.recht;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.view.animation.Animation;import android.view.animation.Animation.AnimationListener;import android.view.animation.AnimationUtils;import android.widget.Button;public class MainActivity extends Activity implements OnClickListener { private Handler mHandler = new Handler(); private Button btn; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn = (Button) findViewById(R.id.getup); btn.setOnClickListener(this); } private void launcherTheRocket() { mHandler.postDelayed(new Runnable() { @Override public void run() { final View rocket = findViewById(R.id.rocket); //初始化 Animation rocketAnimation = AnimationUtils.loadAnimation( getApplicationContext(), R.anim.rocket); //设置动画监听 rocketAnimation .setAnimationListener(new VisibilityAnimationListener( rocket)); //开启 rocket.startAnimation(rocketAnimation); final View cloud = findViewById(R.id.cloud); Animation cloudAnimation = AnimationUtils.loadAnimation( getApplicationContext(), R.anim.cloud); cloudAnimation .setAnimationListener(new VisibilityAnimationListener( cloud)); cloud.startAnimation(cloudAnimation); final View launcher = findViewById(R.id.launcher); Animation launcherAnimation = AnimationUtils.loadAnimation( getApplicationContext(), R.anim.launcher); launcherAnimation .setAnimationListener(new VisibilityAnimationListener( launcher)); launcher.startAnimation(launcherAnimation); } }, 150); } public class VisibilityAnimationListener implements AnimationListener { private View mVisibilityView; public VisibilityAnimationListener(View view) { mVisibilityView = view; } public void setVisibilityView(View view) { mVisibilityView = view; } //动画开始 @Override public void onAnimationStart(Animation animation) { Log.i("START", "..."); if (mVisibilityView != null) { mVisibilityView.setVisibility(View.VISIBLE); // mVisibilityView.setVisibility(View.GONE); } } //动画结束 @Override public void onAnimationEnd(Animation animation) { Log.i("END", "..."); if (mVisibilityView != null) { mVisibilityView.setVisibility(View.GONE); } } @Override public void onAnimationRepeat(Animation animation) { } } @Override public void onClick(View v) { //启动 launcherTheRocket(); }}好的，我们可以来运行一下了
这里我们并没有添加清理缓存的功能，我们在下面实现，这里提供一个工具类DataCleanManager
package com.lgl.data;import java.io.File;import java.math.BigDecimal;import android.content.Context;import android.os.Environment;/** * 本应用数据清除管理器 */public class DataCleanManager { public static String getTotalCacheSize(Context context) throws Exception { long cacheSize = getFolderSize(context.getCacheDir()); if (Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED)) { cacheSize += getFolderSize(context.getExternalCacheDir()); } return getFormatSize(cacheSize); } public static void clearAllCache(Context context) { deleteDir(context.getCacheDir()); if (Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED)) { deleteDir(context.getExternalCacheDir()); } } private static boolean deleteDir(File dir) { if (dir != null && dir.isDirectory()) { String[] children = dir.list(); for (int i = 0; i < children.length; i++) { boolean success = deleteDir(new File(dir, children[i])); if (!success) { return false; } } } return dir.delete(); } // 获取文件 // Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/ // 目录，一般放一些长时间保存的数据 // Context.getExternalCacheDir() --> // SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据 public static long getFolderSize(File file) throws Exception { long size = 0; try { File[] fileList = file.listFiles(); for (int i = 0; i < fileList.length; i++) { // 如果下面还有文件 if (fileList[i].isDirectory()) { size = size + getFolderSize(fileList[i]); } else { size = size + fileList[i].length(); } } } catch (Exception e) { e.printStackTrace(); } return size; } /** * 格式化单位 * * @param size */ public static String getFormatSize(double size) { double kiloByte = size / 1024; if (kiloByte < 1) { return size + "Byte"; } double megaByte = kiloByte / 1024; if (megaByte < 1) { BigDecimal result1 = new BigDecimal(Double.toString(kiloByte)); return result1.setScale(2, BigDecimal.ROUND_HALF_UP) .toPlainString() + "KB"; } double gigaByte = megaByte / 1024; if (gigaByte < 1) { BigDecimal result2 = new BigDecimal(Double.toString(megaByte)); return result2.setScale(2, BigDecimal.ROUND_HALF_UP) .toPlainString() + "MB"; } double teraBytes = gigaByte / 1024; if (teraBytes < 1) { BigDecimal result3 = new BigDecimal(Double.toString(gigaByte)); return result3.setScale(2, BigDecimal.ROUND_HALF_UP) .toPlainString() + "GB"; } BigDecimal result4 = new BigDecimal(teraBytes); return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString() + "TB"; }}使用方法
private DataCleanManager dm;try { //缓存大小 tv.setText(dm.getTotalCacheSize(this));} catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }//清理缓存dm.clearAllCache(MainActivity.this);